Communication data relay system and method of controlling connectability between domains

Abstract

A relay system, comprises interface units for accessing networks, a domain definition module, an connection definition module, a routing module, an address translation module for translating, when forwarding a communication data from one domain to another domain, a source address belonging to the source domain contained in the packet into a proxy host address belonging to the routing destination domain, and an address reverse translation module for translating, when receiving a communication data which has the proxy host address in destination address field, the destination address belonging to the source domain contained in the packet into the address belonging to the routing destination, and a control unit for controlling a connectability for routing between the two or more domains in accordance with definitions of the connection definition module.

1. A relay system relaying between two or more networks to which one or more communication devices are connected, comprising:
 two or more interface units accessing said networks;  
 a domain definition table defining domains as a system framework including one or more networks;  
 an inter domain connection definition table defining connectability between two or more domains;  
 a routing module storing a routing destination of communication data;  
 an address translation module for translating, when forwarding communication data from a first domain to a second domain, a first address belonging to the first domain contained in a source address field of the communication data into a second address being an address of the relay system as recognized in the second domain;  
 an address reverse translation module for translating, when receiving communication data having the second address in a destination address field, the second address into the first address belonging to the first domain; and  
 an inter domain connection judging module controlling connectability for routing between the two or more domains in accordance with definitions of said inter domain connection definition table.  
 
     
     
       2. A relay system according to  claim 1 , wherein said domain definition table defines each domain by information for identifying an interface unit connected to a domain. 
     
     
       3. A relay system according to  claim 1 , wherein said inter domain connection judging module discards communication data when a domain corresponding to an interface unit receiving the communication data, is different from a domain to which the source address of the communication data belongs. 
     
     
       4. A relay system according to  claim 1 , wherein said domain definition table is defined per domain by an address for identifying a network included in the domain. 
     
     
       5. A communication data relay method for relaying between two or more networks to which one or more communication devices are connected, comprising:
 referring to a domain definition table defining domains as a system framework including one or more networks;  
 referring to an inter domain connection definition table for defining connectability between two or more domains;  
 referring to a routing module storing a routing destination of the communication data;  
 translating, when forwarding communication data from a first domain to a second domain, a first address belonging to the first domain contained in a source address field of the communication data into a second address being an address of the relay system as recognized in the second domain;  
 reverse translating, when receiving communication data having the second address in a destination address field, the second address into the first address belonging to the first domain; and  
 controlling connectability for routing between the two or more domains in accordance with definitions of said inter domain connection definition table.  
 
     
     
       6. A relay system according to  claim 1 , wherein said inter domain connection judging module discards communication data when an interface unit receiving the communication data, is different from an interface unit corresponding to the domain to which a source address of the communication data belongs. 
     
     
       7. A relay system according to  claim 1 , wherein said domain definition table is defined per domain by an address for identifying the communication device connected to the network included in the domain.